IMHO speakers have the most influence in the overall sound and character of a system. If you’re already set on your source (RTR) then speakers logically would be the next step. Pick your "sound" and THEN get the requisite electronics. Bookshelf or floor standers? Traditional box speakers or planar? All of those will likely require different electronics to sound their best. With regards to no preamp, I’d reconsider that. For one thing you’ve completely forgone any flexibility with regards to any other sources, not to mention any convenience features like a remote. (Unless your R2R has one) In any case, enjoy the hunt!
Happy listening...
Happy listening...